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retaining wall install and the ground is spongey after compaction!

Discussion in 'Hardscaping' started by Hardscaping, Sep 17, 2008.

  1. Hardscaping

    Hardscaping LawnSite Senior Member
    Messages: 359

    thanks for the help.

    Basically with research on the net and the info you have given me i have decided to dig it up a bit and then fill with 1" stone using fabric around it and then compact and then use a stone base and then use all the gravell i have for behind the wall. gonna cost me an extra 120 bux and about 2 more hours of work. but i guess that is not much of a problem to avoid 3 days of tear out and reinstall due to not being done properly.
  2. PatriotLandscape

    PatriotLandscape LawnSite Bronze Member
    from MA
    Messages: 1,209

    seriously what are you smoking. What the hell would Styrofoam do?
    why did you take a job that you were not qualified to do. beyond being qualified you didn't even have a general understanding of the minimum requirements for install.
  3. kootoomootoo

    kootoomootoo LawnSite Platinum Member
    Messages: 4,369

  4. wurkn with amish

    wurkn with amish LawnSite Senior Member
    Messages: 662

    I hope pink!
  5. Mike33

    Mike33 LawnSite Bronze Member
    Messages: 1,649

    Hardscaping with another crisis! What else is new.
  6. TerraTek

    TerraTek LawnSite Member
    from Toronto
    Messages: 11

    id use spray foam, taht way there will be no drafts or leaks
  7. Hardscaping

    Hardscaping LawnSite Senior Member
    Messages: 359

    well since you guys are just comedians on here, i can come home and have a laugh.

    Don't think for a minute that i cannot build a nice wall, and do it correctly. I have finished the base and the base course blocks as well as most of the wall today. Just have to put another 200 block into the job and clean up.

    I decided to listen to you mrusk somewhat. I didn't dig down 24". i dug out 8 inches lower than originally dug out hit hard ground and then, I put down seperation fabric and then filled in the area with 3\4" clean stone. As well as 6" to 8" behind the wall.

    I have built this wall correctly i used hanson wallstone used bottom three layers for most of job being the double units.

    The wall is level and looks great so far. once done i will show the pics. With the problems incured it took longer than expected but what can ya do.

    The wall is 54 feet long and 95% or the wall is 11 blocks high that is 44" high.

    Each block is stepped back one inch. I have to go back tomorrow and put in the remaining 200 block of the 590 i am using. The homeowner has seen the job every step and is very pleased. Even had someone to come over looking at it, they liked it too.

    There was a lot of dig out and i couldn't get the mini ex in there to do it, because the ground would of caved in. very wet.
  8. Hardscaping

    Hardscaping LawnSite Senior Member
    Messages: 359

    The foam idea that i was talking about was for under walkways it helps stop the shifting from freeze thaw.

    What you do is put down one layer of the 2" foam down throughout the area to be done. then you put down a second layer as you would stack retaining wall blocks, splitting them. Then you install you 6 to 8" base of a gravel compacted in lifts. then you screed you sand and install pavers. this is suppose to act as a base would if it was about 2 to 3 feet deep. also good to use under driveways in same manor but using 8 to 12" of base material.
  9. neighborguy

    neighborguy LawnSite Member
    Messages: 186

    Hardscaping, I have never heard of such a thing. i am not criticizing, just never heard of it. How many times have you done it this method? How long has it been installed? Do you have pictures? I am just curious as we in Wisconsin have to battle the freeze/thaw cycle as you have to in Ontario.

  10. jamo1911

    jamo1911 LawnSite Member
    Messages: 65

    There are a few things you can do to fix this.
    You must achieve 98% standard proctor density in your sub base before you can move to the base. If you are having trouble getting your compaction #'s I suggest you do one of 2 things. 1. wait till it dries out, you could add hydrated lime to help it out but it will be hard to mix in the soil (sounds like clay). while I am on the subject of clay - you should get the sub base tested by a testing company. I know in reality you probably won't do this at this point but you should. Reason being - if the soil has more that 30% passing a #200 sieve it is not stable enough for building a wall on period. It sounds like it is by the way you describe the pumping action. In this case you could use your jumping jack to pound in (what we call in NY) rip-rap. Just softball size chunks of rock. This will in essence change the ratio of passing and not passing the #200 to less than 30%.
    2. you could just excavate out your sub base till you reach solid virgin soil and fill with proper base material. By the way, how wide is your base? it must be at least 3x as wide as the block.
    Have your base tested by the testing company for standard proctor density or buy a dynamic cone penetrometer and do it yourself.

    I know ppl on here are busting your chops - for good reason. If you drive around and see failed walls, well guess how some of them got that way. Contractors that did not know what they are doing. I understand you may have sold the job already. But to be fair to the industry please get the schooling you need. Even if your customer knows this is your first wall, or are not trained, their friends do not. What this means is that if a random person walks in the back yard and looks at this wall after it fails they may lose faith in segmented retaining walls. How many times have you heard pavers don't work, move, etc. It's just bad for the industry to do bad work.
    Good luck and please do it right for all of us who rely on the industry as a whole to have a good rep.

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